The leukotrienes constitute a group of locally acting hormones, produced in living systems from arachidonic acid. The major leukotrienes are Leukotriene B.sub.4 (abbreviated at LTB.sub.4), LTC.sub.4, LTD.sub.4 and LTE.sub.4. The biosynthesis of these leukotrienes begins with the action of the enzyme 5-lipoxygenase on arachidonic acid to produce the epoxide known as Leukotriene A.sub.4 (LTA.sub.4), which is converted to the other leukotrienes by subsequent enzymatic steps. Further details of the biosynthesis as well as the metabolism of the leukotrienes are to be found in the book Leukotrienes and Lipoxygenases, ed. J. Rokach, Elsevier, Amsterdam (1989). The actions of the leukotrienes in living systems and their contribution to various diseases states are also discussed in the book by Rokach.
European patent applications 176,619 and 199,543 (ICI Americas, Inc.) describe a series of heterocyclic compounds which are leukotriene antagonists. The compounds of the present invention differ from the compounds of the prior art by having a large aromatic structure attached at position G.sup.1 or A.sup.1. ##STR2##
Matassa, et al., J. Med. Chem., 33, 1781-1790 (1990) describe a series of indoles and indazoles as being leukotriene antagonists. These compounds differ from those of the present invention principally in the nature of the substituent on the indole nitrogen.